PSMB8 and infectious otitis media: Moreover, the relative mRNA expression of Cxcl1, Cxcl2 and Cxcl3 as well as that of their receptors Cxcr1 and Cxcr2 was significantly reduced in the colon of AOM/DSS-treated LMP7 deficient mice as compared to WT mice (Figure 3D and 3E).